Resorption of albuminoid fluids 111 



be extremely sensitive to the poison of the eel, whilst the converse 

 may also hold good [cf. infra, p. 120]. 



The toxic action of the eel's serum upon the red corpuscles of a 

 great number of Vertebrates is a natural property which demands no 

 previous treatment of the eel. It is the antitoxic power, directed 

 against the ichthyotoxin, which is developed only as a result of the 

 preparation of the animals by the administration of increasing doses 

 of eel's serum. Nevertheless we also find natural antitoxins present 

 in the blood of man or animals that have not been treated and which 

 act against the cell poisons, cytotoxins, so widely distributed in the 

 blood of a large number of species of animals. 



Besredka^ has demonstrated that the blood serum of Man and 

 many Vertebrates contains a substance which prevents the solution of 

 red corpuscles under the influence of blood serums of a different 

 species. To reveal the presence of these antitoxins it is useful to heat 

 the serums to 56° C. and then to add to them red corpuscles of the 

 same species and some haemolytic serum of a different species. 

 Under these conditions the solution of the red corpuscles does not 

 take place, whilst their mixture with haemolytic serum alone, in- 

 evitably provokes haemolysis. 



Along with these natural antihaemolysins there exist a number of 

 artificial antihaemolysins or antihaemotoxins. Jules Bordet^ was the 

 first to draw attention to this important subject. He first obtained 

 these antihaemolysins by injecting blood serum of the fowl, which 

 possesses a very great haemolytic power on the red corpuscles of the 

 rabbit, into individuals of this latter species. After some injections, [119] 

 the serum of these treated rabbits was found to be antihaemotoxic 

 against the fowl's serum. Later^, Bordet obtained a serum against an 

 artificial haemotoxin. The serum of the guinea-pig is innocuous to the 

 red corpuscles of the rabbit. But when rabbit's blood was injected 

 several times into guinea-pigs the serum of the latter became very 

 solvent for the red corpuscles of the rabbit. To prevent this action it 

 is sufficient to inject the haemotoxin of treated guinea-pigs several 

 times into rabbits. The serum of these rabbits becomes antihaemo- 

 toxic and protects the red corpuscles of the rabbit against the solvent 

 action of guinea-pig's serum. 



In the normal haemolytic serums, such as the serums of the eel and 



1 Ann. de I' Inst. Pasteur, Paris, 1901, t. xv, p. 785. 



* Ibid. 1899, t. XIII, p. 285. 



3 Ibid, Paris, 1900, t. xiv, p. 270. 



